Improvement in keys for locks



UNITED STATES yPATENT OFFICE. l

PORTER GLADWIN, OF BOSTON, ASSIGNOE TO HIMSELF AND HORACE M. LEE, OF DOROHESTER, MASSACHUSETTS.

IMPROVEMENTv IN KEYS FOR LOCKS.

Specification forming part of Letters Patent No. 55,582.. dated June l2, 1866.

To all 'whom 'it 'ma/y concern:

Beit known that I, PoETEn A. GLADWIN, of Boston, in the county of Suffolk and State of Massachusetts, have invented an Improved SafetyGuard for Locking-Keys, ot' which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a view of my improved safetyguard detached. Fig. 2 is a view of my safetyguard attached to the bow of a key turned at right angles to the direction of the key-hole. Fig. 3 represents a modification of my safetyguard.

The object ol" my invention is to provide a convenient and reliable means of fastening` a key within its key-hole, thus preventing the k y from being turned and pushed out to ullow of inserting a duplicate key, or the use of any instrument for picking the lock and my invention consists in an attachment or guard, one end of the shank of which is bent around to admit of its being slipped over the key-bow or handle of the key when turned in the lock after the bolt is tl1ro\vn`ior\\'ard, the bent portion of the shank being provided with a hook which holds the key-bow, and prevents the removal of the key from the key-hole or the bolt from being withdrawn.

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it out.

In Fig. 2 of the said drawings, A represents akey in the position it would occupy within a lock when turned therein and the bolt thrown forward. a is the key-hole, (seen in red.) B is a dat strip of meta-l or other suitable material having one of its ends b bent around in the form shown in Figs. l and 2, and having pivoted thereto, at c, the curved hook C, which is raised when the key-bow d is to be released by the projection c. After the key A has been .turned in the-lock, as shown in Fig. 2, the

outer end, j', of the shank B is passed into the key-hole a., beyond the endg of the bit and spindle of the key, the upperedge, h, of the shank B extending longitudinally under the key; and the bent portion of the shank B being slipped over the key-bow d, the hook C is thrown down in front, coniiuing the key-bow, as seen in Fig. 2.

lt will thus be seen that when forceps or other instruments are applied to turn the key the upper and lower edges of the shankB will strike against the sides ofthe key-hole c, and prevent the spindle from rotatingand thebolt from being Withdrawn.

Instead of the bent portion of the shank B being provided with a hook, C, a screw, D, may be used to close the opening for the reception of the key-bow, as seen in Fig. 3, without departing from the spirit of my invention.

What I claim as myinvention, and desire to secure by Letters Patent, is-

The within-described safety-guard for locking-keys, consisting of the shank B, in combination with the. hook C, substantially as described.

PORTER A. GLADWIN.

Witnesses:

P. E. TESGEEMACHEE', N. W. STEARNs. 

